Earlier this month Brafton reported that Google is changing search ad display URLs to lowercase letters. A Webmaster World thread indicates that the company has started implementing this new feature among its ad partners.

On Friday, one Webmaster World user said, "We noticed [lowercase URLs] rolling out across all of our ads today. Has anyone been badly affected by it so far?"

Google hopes that none of its partners will be "badly affected." In its initial announcement about the change, the company said, "we experiment with hundreds of subtle variations of the Google search results page, testing everything from font sizes and colors to layouts and spacing." Officials believe the URL change will improve partners’ metrics, including clickthrough rates.

This could be good news to marketers, as Brafton has reported that paid search is poised for growth in 2011 based on increased search ad spend during Q4 2010. According to SearchIgnite, search spend demonstrated a 35.3 percent year-over-year increase during the fourth quarter of last year.